Folding baby stroller

ABSTRACT

A baby stroller for transporting a child is disclosed. This baby stroller has a folding mechanism to facilitate folding for easier stowing and transporting. The folding mechanism, a unique feature of the design is directed toward compactness, ease of use, reliability, and reduction in manufacturing costs.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to pending U.S. patent application Ser.No. 12/611,363 filed Nov. 3, 2009, which claims priority to U.S. patentapplication Ser. No. 11/118,621 filed on Apr. 28, 2005 which claimspriority to U.S. Provisional Patent Application No. 60/567,325 filed onApr. 30, 2004, which are all incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to baby strollers, and more particularly,to all-terrain baby strollers that can be folded.

2. Description of the Related Art

Traditionally, baby strollers have been used to push an infant slowly ona relatively hard smooth floor or sidewalk. As a result, the strollerswere made small and light. These strollers work well enough at slowspeed, but are extremely unwieldy and even dangerous on rough surfacesor at high speeds.

All-terrain baby strollers have been designed to overcome theseproblems. These strollers typically employ much larger wheels, oftenlarge bicycle tires. The stroller frame members are constructed of metaltubular stock and durable plastic frame connectors or other durablematerial to connect the frame members together to handle the heavy dutyuse they may receive. The frame connectors are used also to rotate orpivot one frame member relative to another, and are used to removablyconnect other frame members together.

Some advanced designs on all-terrain strollers have allowed for acertain degree of folding of the all-terrain baby strollers into lessthan a desirable complications that increase cost and reduce reliabilityand ease of use.

BRIEF SUMMARY OF THE INVENTION

The present invention resides in a folding baby stroller and a foldingmechanism usable with a foldable baby stroller.

The folding mechanism includes a folding assembly having a first andsecond rotatable members rotatably mounted to rotate relative to eachother. The first rotatable member is positioned for rotation in a firstrotation plane and the second rotatable member is positioned forrotation in a second rotation plane, the first and second rotationplanes being spaced apart. The first rotatable member has a first gearand the second rotatable member has a second gear. The folding assemblyfurther has a third gear and a fourth gear configured to rotate togetheras a unit. The third gear is positioned in driving engagement with thefirst gear and the fourth gear is positioned in driving engagement withthe second gear so that the first rotatable member and the secondrotatable member rotate relative to each other in geared coordination.The first rotatable member is configured for attachment to a first oneof first, second and third frame members, the second rotatable memberbeing configured for attachment to a different second one of the first,second and third frame members, and the third and fourth gearsconfigured for support by another different third one of the first,second and third frame members.

The first gear of the folding mechanism may have a first pitch andsecond gear a second pitch different than the first pitch, and the thirdgear may have a third pitch compatible with the first pitch of the firstgear and the fourth gear may have a fourth pitch compatible with thesecond pitch of the second gear.

In one embodiment of the folding mechanism, the first rotatable memberhas a first aperture and the first gear is formed in a first edgeportion of the first rotatable member defining the first aperture, andthe second rotatable member has a second aperture and the second gear isformed in a second edge portion of the second rotatable member definingthe second aperture. The third gear is positioned in the first apertureand the fourth gear is positioned in the second aperture. The first andsecond edge portions may be radially displaced from each other. Further,the first and second rotatable members each may have a face portion withthe face portions arranged in face-to-face juxtaposition.

The first and second rotatable members may be rotatably mounted on apivot member for rotation about a common axis of rotation, and the thirdand fourth gears may be coaxially mounted to rotate about an axisparallel to and spaced apart from the common axis of the first andsecond rotatable members.

In one embodiment of the folding mechanism the third gear has a firstnumber of gear teeth and fourth gear has a second number of gear teethdifferent than the first number, and the third gear has a pitchcompatible with the pitch of the first gear and the fourth gear has apitch compatible with the pitch of the second gear.

The folding assembly may be used as part of a foldable baby strollerframe or other device. The baby stroller typically has a front wheelsupport, a rear wheel support and a handle member. The folding assemblymay include a pivot member, a first rotatable member with a firstaperture having a first gear, and a second rotatable member with asecond aperture having a second gear. The first and second rotatablemembers are rotatably coupled to the pivot member to rotate about commonaxis of rotation. A third gear is positioned in both the first andsecond apertures in driving engagement with the first gear and thesecond gear so that the first rotatable member and the second rotatablemember rotate relative to each other in geared coordination.

The first gear may have a first pitch and second gear a second pitchdifferent than the first pitch, and the third gear may include a firstgear portion with the first pitch and a second gear portion with thesecond pitch. The first and second portions of the third gear areconfigured to rotate as a unit. The first gear portion of the third gearis positioned in the first aperture in driving engagement with the firstgear and the second gear portion of the third gear is positioned in thesecond aperture in driving engagement with the second gear.

The pivot member is configured to be supportingly engaged by one of thefront wheel support, rear wheel support and handle member; the firstrotatable member is configured to be attached to a different one of thefront wheel support, rear wheel support and handle member; and thesecond rotatable member is configured to be attached to anotherdifferent one of the front wheel support, rear wheel support and handlemember.

The first gear is formed in a first edge portion of the first rotationmember defining the first aperture and the second gear is formed in asecond edge portion of the second rotation member defining the secondaperture. In the depicted implementation the first and second edgeportions are radially displaced from each other.

The first and second apertures may be elongated with the elongated firstand second apertures at least in part overlapping. The first gear mayhave a first pitch diameter, and the second gear a second pitchdiameter, with the first pitch diameter and the second pitch diameternot being the same. The first gear may be positioned radially outward ofthe second gear.

The depicted implementation has the first pitch diameter of the firstgear sized to rotate the one of the front wheel support, rear wheelsupport and handle member to which the first rotatable member isconfigured to be attached through a first angle of rotation from afolded position to an unfolded position of the foldable baby strollerframe, and the second pitch diameter for the second gear is sized torotate the one of the front wheel support, rear wheel support and handlemember to which the second rotatable member is configured to be attachedthrough a second angle of rotation from a folded position to an unfoldedposition of the foldable baby stroller frame, with the first and secondangles of rotation not being the same.

The first rotatable member has an arm configured to be attached to theone of the front wheel support, rear wheel support and handle member towhich the first rotatable member is configured to be attached, and thesecond rotatable member has an arm configured to be attached to the oneof the front wheel support, rear wheel support and handle member towhich the second rotatable member is configured to be attached.

The folding assembly may include a movable member, and the first andsecond rotatable members may each further include a notch to receive themember therein when the first and second rotatable members are rotatedabout the pivot member to position the notches of the first and secondrotatable members in alignment.

The folding assembly may also include a housing in which the pivotmember is positioned. The housing is configured to be attached to theone of the front wheel supports, rear wheel supports and handle membersto which the pivot member is configured to be supportingly engaged.

Other features and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an isometric view of an exemplary implementation of a babystroller embodying the present invention shown in a fully unfolded stateready for usage.

FIG. 2 is an isometric view of the stroller frame of FIG. 1 without aseat and a leg guard.

FIG. 3 is a front elevational view of the stroller frame of FIG. 2.

FIG. 4 is a side elevational view of the stroller frame of FIG. 2.

FIG. 5 is a side elevational view of the stroller frame of FIG. 2 shownin the partially folded state.

FIG. 6 is a side elevational view of the stroller frame of FIG. 2 shownin a fully folded state with both left and right front supports and leftand right side handle supports being rotated about their respective sidefolding assemblies toward respective side rear wheel supports and withthe front wheel removed.

FIG. 7 is an exploded isometric view of the right side folding assemblyof the implementation shown in FIG. 1, the left side folding assemblybeing a mirror image thereof.

FIG. 8 is an enlarged, fragmentary, right side elevational view of theright side folding assembly of FIG. 7 with its outer half housingremoved and in the fully unfolded state.

FIG. 9 is a fragmentary, left side elevational view of the right sidefolding assembly of FIG. 7 with its inner half housing removed and inthe partially unfolded state.

FIG. 10 is an enlarged isometric view of a pinion gear and pin used inan alternative embodiment of the folding assembly shown in FIG. 12 wherethe pinion gear has two gear portions.

FIG. 11 is an enlarged isometric view of a pinion gear and pin used inyet another alternative embodiment of the folding assembly shown in FIG.13 where the pinion gear is comprised of two gears affixed together foruse.

FIG. 12 is an exploded isometric view, corresponding to FIG. 7, of theright side folding assembly of an alternative embodiment of the foldingassembly, the left side folding assembly being a mirror image thereof.

FIG. 13 is an exploded isometric view, corresponding to FIG. 7, of theright side folding assembly of yet another alternative embodiment of thefolding assembly, the left side folding assembly being a mirror imagethereof.

FIG. 14 is an exploded isometric view, corresponding to FIG. 7, of acenter folding assembly used in a double baby stroller shown if FIG. 15having two release levers.

FIG. 15 is an isometric view of an exemplary implementation of a doublebaby stroller embodying the present invention shown in a fully unfoldedstate ready for usage but without a seat and a leg guard.

DETAILED DESCRIPTION OF THE INVENTION

As shown in the drawings for purposes of illustration, the presentinvention is embodied in an all-terrain baby stroller 10, as shown inFIG. 1, having a foldable, tubular metal frame 12 and a transverselyextending rear axle assembly 14 with a transverse, non-rotating tubularrear axle 15. Left and right side rear wheels 16 are rotatably mountedto the ends of the rear axle assembly 14. The forward end of the frame12 has a single front wheel 18 rotatably mounted thereto.

The frame 12 has no base frame members extending rearwardly from thefront wheel 18 to the rear axle assembly 14 as do most conventionalall-terrain strollers. Instead, the frame 12 includes left and rightside, downwardly and forwardly sloping front wheels frame members orsupports 20, which each extend downward from a corresponding one of leftand right side folding assemblies 22 in a converging configuration tothe front wheel 18. A forward free-end 20 a of each of the left andright side front wheel supports 20 has a plastic front wheel connector20 b fixedly attached thereto and a corresponding one of the left andright ends of an axle 18 a of the front wheel 18 removably attachedthereto to mount the front wheel to the stroller frame 12.

The front wheel supports 20 are interconnected by a foot rest 23 thatspans between them toward but rearward of their forward free-ends 20 aand that is fixedly attached to each at a position rearward of the axle18 a of the front wheel and extending partially over the front wheel 18.As a result of the interconnection provided by the foot rest 23, andalso the front wheel 18 when attached to the left and right side frontwheel connectors, the left and right side front wheel supports 20 form astationary unit with respect to the left and right side foldingassemblies 22 upon folding and unfolding of the stroller 10, as will bedescribed in greater detail below.

The frame 12 also includes left and right side, upwardly and rearwardlysloping handle frame members or supports 24, which each extend upwardfrom the corresponding one of the left and right side folding assemblies22 in a generally parallel configuration to a handle 26 extendingbetween the left and right side handle supports. The handle 26 iscovered by a foam grip. The handle supports 24 are interconnected by thehandle 26 that spans between them at their rearwardmost and uppermostextension and that is fixedly attached to each.

As a result of the interconnection provided by the handle 26, the leftand right side handle supports 24 move as a unit with respect to theleft and right side folding assemblies 22 upon folding and unfolding ofthe stroller 10, as will be described in greater detail below. It isnoted that in lieu of the interconnecting handle 26, the handle supports24 may each be provided with a handle portion at the upper end thereofsuch as used with umbrella style strollers.

In the illustrated embodiment of the invention the left and right sidehandle supports 24 and the handle 26 are formed as an integral unit bybending a single length of aluminum tube. The left and right side handlesupports 24 are movable relative to the left and right side front wheelsupports 20 for folding of the stroller 10 and do not together form anintegrated rigid upper frame.

The frame 12 also includes left and right side, downwardly andrearwardly sloping rear wheel frame members or supports 30, which eachextend downward from the corresponding one of the left and right sidefolding assemblies 22 in a generally parallel configuration to the rearaxle assembly 14. A rearward free-end 30 a of each of the left and rightside rear wheel supports 30 is fixedly attached to the tubular rear axle15 toward a corresponding one of the left and right ends of the tubularrear axle 15. The rear wheel supports 30 are interconnected by the rearaxle assembly 14 that spans between them at the rearward free-ends 30 athereof. A cross-frame member 31 with a U-shape extends between the leftand right side rear wheel supports 30. As a result of theinterconnection provided by the rear axle assembly 14 and thecross-frame member 31, the left and right side rear wheel supports 30move as a unit with respect to the left and right folding assemblies 22for folding and unfolding of the stroller 10, as will be described ingreater detail below. The left and right side rear wheel supports 30 arealso movable relative to the left and right side front wheel supports 20and the left and right side handle supports 24 for folding of thestroller 10. Further, the left and right side rear wheel supports 30 andthe rear axle assembly 14 connected thereto do not form a part of a baseframe extending between the rear and front wheels 16 and 18. Much of thestructural strength of the stroller 10 and the interconnection of thefront wheel supports 20, the handle supports 24, and the rear wheelsupports 30 are provided by the centrally positioned left and right sidefolding assemblies 22, and not by a base frame.

In the illustrated embodiment of the stroller 10, the left and rightside front wheel supports 20, the left and right side handle supports24, and the left and right side rear wheel supports 30 are made fromaluminum tube. Suitable alternative materials may be used.

The left and right outward ends of the tubular rear axle 15 are open andinternally threaded to receive a threaded stub axle 32 forming a part ofthe corresponding one of the left and right rear wheels 16. A lock nut(not shown) when tightened against the face of the stub axle 32 locksthe stub axle against loosening during usage of the stroller 10.Alternative constructions may be used to fixedly or removably attach therear wheels 16 to the tubular rear axle 15, and any suitable alternativemanner of mounting the rear wheels 16 to the real wheel supports 30 maybe used.

The frame 12 of the stroller 10 is shown in FIG. 1 in the fully unfoldedstate with a fabric seat 33 a, and a fabric leg support and guard 33 b.The seat 33 a is suspended from the left and right side handle supports24, and the leg guard 33 b spans between and is supported by the leftand right side front wheel supports 20. For purposes of illustration,the frame 12 is shown in FIG. 2 without the seat 33 a and the leg guard33 b.

For the depicted implementation, user operation of the left and rightside folding assemblies 22 will now be described. The left and rightside folding assemblies 22 have the same construction, with one beingthe mirror image of the other, and the description below, while in thesingular, is applicable to both. Each of the left and right rear wheelsupports 30 supports an inwardly extending lever 34, which has apredominantly vertical orientation, as shown in FIG. 3, when the frame12 of the stroller 10 is locked in the fully unfolded position. To beginthe procedure to fold the frame 12, each of the levers 34 is pulledupward and inward as depicted by arrows R1 to thereby put the left andright side folding assemblies 22 in an unlocked state as furtherexplained below. A strap (not shown) may be connected by its ends to thelevers 34 to facilitate movement of both levers at the same time.

With each of the left and right folding assemblies 22 in an unlockedstate, the left and right handle supports 24, along with the handle 26,and the left and right front wheel support 20, along with the frontwheel 18, can be rotated about the left and right folding assemblies,respectively, toward the left and right rear wheel supports 30,respectively, as depicted by arrows R2 shown in FIG. 4. As shown, whenthe stroller 10 is folded, the folding assemblies 22 allow a greaterrotation angle for the handle supports 24 (greater than 90°) than forthe front wheel supports 20 (less than 90°). As explained further below,the front wheel supports 20 move in geared coordination with movement ofthe handle supports 24. As the frame 12 is being folded, the front wheelsupports 20 are rotated clockwise about the folding assemblies 22 asviewed in FIG. 4, while the handle supports 24 are also rotatedcounterclockwise about the folding assemblies as viewed in FIG. 4. Theframe 12 is shown in a partially folded state in FIG. 5. In a fullyfolded state, both the front wheel supports 20 and the handle supports24 have been rotated in geared coordination with each other about thefolding assemblies 22 to be positioned in close proximity to the rearwheel supports 30 as shown in FIG. 6. To do so the front wheel 18 isremoved.

The right side folding assembly 22 is shown in exploded view in FIG. 7and includes a laterally outward positioned forward rotatable member 35′and a laterally inward rearward rotatable member 35″, each with a flatface facing toward the other. The forward rotatable member 35′ has aplate or disk 36′ with a central plate portion having a central aperture37′. The forward rotatable member 35′ also includes a notch 38′, aradially outward internal gear 39′ in an elongated aperture 41′, and anarm 40′. The rearward rotatable member 35″ has a plate or disk 36″ witha central plate portion having a central aperture 37″. The rearwardrotatable member 35″ also includes a notch 38″, a radially inwardinternal gear 39″ in an elongated aperture 41″, and an arm 40″. For eachof the rotatable members 35′ and 35″, the disks 36′ and 36″ and the arms40′ and 40″ are depicted as being formed as part of a single flat platepiece; however, in other implementations the disks and arms areindividual pieces that are fixedly attached together.

The rotatable members 35′ and 35″, along with a corresponding one of therear wheel supports 30, are contained between inner and outer slottedhalves of a housing 42 that allow the arms 40′ and 40″ to protrudeoutside of the housing. The inside wall of each half of the housing 42has a recess 42 a sized and shaped such that when the two halves of thehousing are positioned together, the recesses form a cavity to receivean upper free-end portion 30 b of the corresponding rear wheel support30 therein and an upper free-end portion of the cross-frame member 31. Abolt (not shown) extends through an aperture 42 f in each half of thehousing 42 and through an aperture 30 c in the upper free-end portion 30b of the rear wheel support 30 and an aperture of the upper free-endportion of the cross-frame member 31 to securely clamp the rear wheelsupport and the cross-frame member between the inner and outer halves ofthe housing.

The central apertures 37′ and 37″ of the disks 36′ and 36″,respectively, are sized to receive a bushing 43 therethrough having alength longer than the cumulative thickness of the two disks. Therotatable members 35′ and 35″ are rotatably mounted on the bushing forrotation within the housing 42 in parallel rotation planes about an axisof rotation transverse to the plane of the disks 36′ and 36″. The endportions of the bushing extending beyond the central apertures 37′ and37″ each have a circumferential groove 43 a to receive a C-clip 43 b toretain the bushing 43 in place. The bushing 43 also extends through awasher 43 d positioned between the disks 36′ and 36″ of the rotatablemembers 35′ and 35″ to serve as a spacer and bearing surface forrotational movement of the rotatable members about the bushing 43. Eachof the disks 36′ and 36″ has a flat face in face-to-face juxtapositionwith the flat face of the other disk with the washer 43 d positionedtherebetween.

The end portions of the bushing 43 extending beyond the C-clip 43 b areeach positioned in and retained by a retaining cup 42 b formed by theinside wall of a correspondingly positioned one of the inner and outerhalves of the housing 42. Each of the inner and outer halves of thehousing 42 has an aperture 42 c in communication with the correspondingretaining cups 42 b. The bushing 43 has a longitudinally extendingcentral aperture 43 c aligned with apertures 43 b of inner and outerhalves of the housing 42, and sized to receive a bolt 45 therethroughthat extends fully through the inner and outer halves of the housing. Anut 45 a is threaded onto a threaded end portion of the bolt 45 to clampthe inner and outer halves of the housing 42 of the folding assembly 22securely together with the disks 36′ and 36″ freely rotatable on thebushing 43 and being spaced apart by the washer 43 d, and with the arm40′ extending forwardly through a forward portion of a slot 42 e in thehousing and the arm 40″ extending rearwardly through a rearward portionof the housing slot. The arms 40′ and 40″ are flat elongated plates.

As noted above, the disks 36′ and 36″ of the rotatable members 35′ and35″ have their flat faces in face-to-face juxtaposition. This provideslaterally adjacent parallel plates with elongated apertures 41′ and 41″,each having the gear teeth of a corresponding one of the radiallyoutward and inward gears 39′ and 39″ formed along an edge portion of thecorresponding one of the elongated apertures 41′ and 41″. The gear teethof the radially outward gear 39′ of the disk 36′ are formed along theradially outward edge of the elongated aperture 41′, and the gear teethof the radially inward gear 39″ of the disk 36″ are formed along theradially inward edge of the elongated aperture 41″. The planar disks 36′and 36″ are arranged in spaced apart parallel planes, and the radiallyoutward and inward gears 39′ and 39″ are similarly arranged in spacedapart parallel planes and not in a common plane or in direct engagementwith each other. The elongated apertures 41′ and 41″ are positioned onthe disks 36′ and 36″ so as to be at least in part overlapping duringthe rotation of the rotatable members 35′ and 35″ between the folded andunfolded states of the stroller 10.

A pinion gear 44 is positioned within the elongated apertures 41′ and41″ in simultaneous geared engagement with both the radially outwardgear 39′ of the forward rotatable member 35′ and the radially inwardgear 39″ of the rearward rotatable member 35″. The pinion gear 44 ispositioned to extend through and beyond each of the elongated apertures41′ and 41″ of the disks 36′ and 36″ at a position where the elongatedapertures overlap during folding and unfolding of the stroller 10, andspan fully between the radially outward and inward gears 39′ and 39″ ofthe disks 36′ and 36″ in simultaneous geared engagement with both of thegears. The pinion gear 44 transmits the driving rotational force betweenthe front wheel supports 20 and the handle supports 24 which causes oneto rotate in response to rotation of the other.

The pinion gear 44 is rotatably mounted on a pin 44 a that has each ofits end portions extending beyond the pinion gear 44 positioned in theaperture of a flat bushing 44 b and rotatably retained by the flatbushing. Each of the flat bushings 44 b is positioned in and retained bya retaining cup 44 c formed by the inside wall of a correspondinglypositioned one of the inner and outer halves of the housing 42. As such,the pinion gear 44 is supported by the housing 42, which is rigidlyattached to the corresponding one of the rear wheel supports 30 formovement therewith, of course, being rotatable about the axis of the pin44 a. With such arrangement, the pinion gear 44 is rotatable about anaxis of rotation transverse to the plane of the disks 36′ and 36″, andparallel to and spaced apart from the axis of rotation of the disks 36′and 36″.

The pinion gear 44 engages both the radially outward gear 39′ of theforward rotatable member 35′ and the radially inward gear 39″ of therearward rotatable member 35″. Consequently, through the pinion gear 44,the radially outward gear 39′ and the radially inward gear 39″ aremutually drivingly engaged with each other so that if either is rotated,the rotational force is transmitted through the pinion gear to the otherto cause the other to also rotate about the bushing 43. As such, if thefront wheel supports 20 or the handle supports 24 are rotated relativeto the rear wheel supports 30, the other of the front wheel supports andthe handle supports is driven to rotate as well.

The radially outward and inward gears 39′ and 39″ have the same pitchsince the pinion gear 44 engages both, but each has a larger pitchdiameter than the pinion gear. However, the radially inward gear 39″have a smaller radius of curvature or pitch diameter than the radiallyoutward gear 39′, thus the resulting rotational movement of the rearwardrotatable member 35″ will be greater than the rotational movement of theforward rotatable member 35′. In other words, for any amount the piniongear 44 is rotated, the rearward rotatable member 35″ and hence thehandle support 24 attached thereto will rotate more than the forwardrotatable member 35″ and hence the front wheel support 20 attachedthereto. This is useful since as noted above, and as shown in FIG. 4, tofold the front wheel supports 20 and the handle supports 24 tightlyabout the rear wheel supports 30 requires a greater rotation angle forthe handle supports (in one embodiment about) 108° than for the frontwheel supports (in that same embodiment about 72°). In anotherembodiment the rotation angle for the handle supports and the frontwheel supports is the same (in the second embodiment about 90° foreach).

The pitch diameter for each of the radially outward gear 39′ of theforward rotatable member 35′ and the radially inward gear 39″ of therearward rotatable member 35″, and the pitch diameter of the pinion gear44, are selected to produce the desired ratio of rotational movement forthe forward and rearward rotatable members 35′ and 35″ to fold thestroller 10 into a compact form with the handle supports 24 and thefront wheel supports 20 nested tightly against the rear wheel supports30. However, while the ability to select different pitch diameters forthe radially outward and inward gears 39′ and 39″ is helpful, even agreater degree of design flexibility may be desirable.

In another embodiment of the folding assembly 22 shown in FIGS. 10 and12, a pinion gear 44′ is shown having first and second pinion gearportions 44 x and 44 y, with the first pinion gear portion having afirst pitch, a first pitch diameter and a first number of gear teeth,and the second pinion gear portion having a different second pitch, asecond pitch diameter and a different second number of gear teeth. Thefirst and second pinion gear portions 44 x and 44 y are made as a singlepart and rotate together as a unit in coaxial arrangement on the pin 44a, but are essentially two pinion gears, each with its own gearparameters. The first pinion gear portion 44 x is positioned to engagethe radially outward gear 39′ and has a pitch corresponding thereto andfive gear teeth, and the second pinion gear portion 44 y is positionedto engage the radially inward gear 39″ and has a pitch correspondingthereto and four gear teeth. The first and second pinion gear portions44 x and 44 y may have the same or different pitch diameters. In suchmanner, the radially outward and inward gears 39′ and 39″ and the firstand second pinion gear portions 44 x and 44 y that engage them,respectively, may be designed with gear parameters to produce a widerrange of differing amounts of rotational movement of the forward andrearward rotatable members 35′ and 35″ when folding and unfolding thestroller 10. In effect, there is more design freedom and flexibilitypermitted since the radially outward gear 39′ and the first pinion gearportion 44 x pair can be designed with first gear parameters to producea first rotational movement of the forward rotatable member 35′, and theradially inward gear 39″ and the second pinion gear portion 44 y paircan be designed with different second gear parameters to produce adifferent second rotational movement of the rearward rotatable member35″, with independence in the first and second gear parameters selected.

As noted above, with the first embodiment described only the pitchdiameters of the radially outward and inward gears 39′ and 39″ differed,but in the embodiment of FIGS. 10 and 12, the radially outward gear 39′and the first pinion gear portion 44 x pair and the radially inward gear39″ and the second pinion gear portion 44 y pair can be designedessentially independent of the other to produce a desired result, suchas a desired ratio of rotational movement of the radially outward gear39′ and the radially inward gear 39″, and hence the desired ratio ofrotational movement of the forward and rearward rotatable members 35′and 35″ when folding and unfolding the stroller 10. For example, thispermits design of the folding assemblies 22 with more control over theamount of movement of both the handle supports 24 and the front wheelsupports 20 relative to the rear wheel supports 30 resulting duringfolding of the stroller 10 and hence allows folding into a compact formwhere the handle supports and the front wheel supports can be moved tonest tightly against the rear wheel supports.

In yet another embodiment of the folding assembly 22 shown in FIGS. 11and 13, a pinion gear 44″ is shown having first and second pinion gears44 xx and 44 yy made as separate parts but fixedly attached together forrotation together as a unit on the pin 44 a, such as by welding, aninsertion pin or some other manner. Alternatively, the first and secondpinion gears 44 xx and 44 yy may be keyed to the pin 44 a so long as thepin is free to rotate. The first pinion gear 44 xx has a first pitch, afirst pitch diameter and a first number of gear teeth (shown as five inthis embodiment), and the second pinion gear 44 yy has a differentsecond pitch, a second pitch diameter and a different second number ofgear teeth (shown as four in this embodiment). The first pinion gear 44xx is positioned to engage the radially outward gear 39′, and the secondpinion gear 44 yy is positioned to engage the radially inward gear 39″.As above, the radially outward gear 39′ and the first pinion gear 44 xxpair and the radially inward gear 39″ and the second pinion gear 44 yypair can be designed with gear parameters essentially independent of theother to providing greater flexibility in designing the foldingassemblies 22 to produce a desired ratio of rotational movement of theradially outward gear 39′ and the radially inward gear 39″, and hencethe desired ratio of rotational movement of the forward and rearwardrotatable members 35′ and 35″ when folding and unfolding the stroller10.

The length of the radially outward gear 39′ of the forward rotatablemember 35′ and the radially inward gear 39″ of the rearward rotatablemember 35″, and also the length of the elongated apertures 41′ and 41″within which the pinion gear 44 is positioned, impact the amount ofrotation possible for the forward and rearward rotatable members 35′ and35″. The range of movement is limited by stops 51′ and 51″ attached tothe perimeter portion of the forward and rearward rotatable members 35′and 35″, respectively. Each of the stops 51′ and 51″ extends laterallytoward the adjacent rotatable member and radially outward of theperimeter of the adjacent rotatable member. The stops 51′ and 51″ areattached to the rotatable members 35′ and 35″ at positions along theperimeter of the rotatable member to which attached such that when therotatable members are rotated to place the folding assemblies 22 in thefully unfolded state, as shown in FIG. 8, the stops 51′ and 51″ are inengagement and prevent further rotational movement of the rotatablemembers in that rotational direction. In the depicted implementation,the stops 51′ and 51″ are positioned to allow a rotation angle for thehandle supports 24 of about 108° and for the front wheel supports 20 ofabout 70°.

It should be understood that while in the depicted implementation thefront wheel supports 20 and the handle supports 24 are attached to therotatable members 35′ and 35″ of the left and right side foldingassemblies 22 (and the rear wheel supports 30 fixedly attached to thehousing 42), other implementations may have the rear wheel supports 30and the handle supports 24 attached to the rotatable members 35′ and 35″of the folding assemblies 22 (and the front wheel supports 20 fixedlyattached to the housing 42) such that they rotate to fold about thefront wheel supports. Similarly, the rear wheel supports 30 and thefront wheel supports 20 may be attached to the rotatable members 35′ and35″ of the folding assemblies 22 (and the handle supports 24 fixedlyattached to the housing 42) such that they rotate to fold about thehandle supports.

To prevent the unintended folding of the stroller 10 when the foldingassemblies 22 are in a fully unfolded state, as shown in FIG. 8, eachfolding assembly has a releasable locking mechanism with a slidablymounted head 50 having a locking lug 52. A spring 54 applies a biasforce to the head 50 to maintain the locking lug 52 in contact with asmooth, rounded perimeter portion of each of the disks 36′ and 36″ ofthe folding assembly as the rotatable members are rotated close to thestroller fully unfolded state. The notches 38′ and 38″ of the disks 36′and 36″ are positioned along a reinforced perimeter portion of the disksin a location where when the stroller 10 reaches the fully unfoldedstate, the notches are in alignment and the spring 54 will drive thehead 50 forward to position the locking lug 52 in both notches, andhence prevent rotation of the disks toward the folded state. The portionof the disks 36′ and 36″ around the notches 38′ and 38″ has increasedthickness for added strength.

The head 50 is slidably mounted in the housing 42 at a position abovethe recess 42 a receiving the upper free-end portion 30 b of the rearwheel support 30. The upper end of the spring 54 engages the head 50 andthe lower end engages a spring support 56 positioned inside the upperfree-end portion 30 b of the rear wheel support 30. The lever 34 for thefolding assembly 22 is pivotally mounted to the rear wheel support 30and has a nose portion extending through an aperture in the head 50 andin engagement with a pin within the head so that when the lever 34 ispulled upward and inward as depicted by the arrows R1 in FIG. 3, thehead 50 is moved downward, away from the disks 36′ and 36″, therebycausing the locking lug 52 to be retracted from the notches 38′ and 38″and permitting the disks 36′ and 36″ to rotate toward the fully foldedstate shown in FIG. 6 in a generally clam shell movement to position thehandle supports 24 and the front wheel supports 20 nested tightlyagainst the rear wheel supports 30. The folding assembly 22 is shown inFIG. 9 between the unfolded and folded states with the locking lug 52 ofthe head 50 retracted from the notch 38′ and 38″.

While the spring 54 supplies enough force to the head 50 to keep thelocking lug 52 in the notches 38′ and 38″ to lock the stroller 10 in thefully unfolded state, the force is not so great as to require undueforce to be applied to the lever 34 by the user to retract locking lugfrom the notches when the folding assembly is to be folded.

Each of the left and right side folding assemblies 22 has thecorresponding left or right front wheel support 20 bolted onto the arm40′ of the forward rotatable member 35′ and the corresponding left orright handle support 24 bolted onto the arm 40″ of the rearwardrotatable member 35″.

It should be understood that while the rotatable members 35′ and 35″were depicted as including the disks 36′ and 36″, in otherimplementations the rotatable members 35′ and 35″ may have other shapes.

Another embodiment of an all-terrain baby stroller 10′ is shown in FIG.15. This embodiment has the basic same design as the stroller 10, but isdesigned to carry two children is side by side arrangement. The frame 12of the stroller 10′, in addition to having the left and right side framesupports 24, has a center frame support 24′ which extends upward from acenter folding assembly 22′ (shown in FIG. 14) of the same constructionas the previously described folding assemblies 22, except the centerfolding assembly 22′ has left and right side outwardly extending levers34. Either of the levers for the center folding assembly 22′ may bepulled upward and outward to place the center folding assembly 22′ in anunlocked state. Much as with the folding assembly 22 described above,each lever 34 for the center folding assembly 22′ is pivotally mountedto a rear wheel support 30′ and has a nose portion extending through anaperture in the head 50 of the center folding assembly 22′, althoughfrom opposite sides thereof. Movement of either lever 34 when pulledupward and outward causes the head 50 of the center folding assembly 22′to moved downward, away from the disks 36′ and 36″ of the center foldingassembly 22′, thereby causing the locking lug 52 to be retracted fromthe notches 38′ and 38″ and permitting the disks 36′ and 36″ to rotatetoward the fully folded state. A strap (not shown) may be connected byits ends to the lever 34 of the left side folding assembly 22 and to theleft side lever 34 of the center folding assembly 22′, and another strap(not shown) may be connected by its ends to the lever 34 of the rightside folding assembly 22 and to the right side lever 34 of the centerfolding assembly 22′ to facilitate movement of both levers to which thestrap is connected at the same time.

From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

The invention claimed is:
 1. A stroller, comprising: a pivot member; afirst rotatable member with a first aperture having a first gear,wherein the first gear is formed at a first edge portion of the firstrotatable member defining a portion the first aperture; a secondrotatable member with a second aperture having a second gear, whereinthe second gear is formed at a second edge portion of the secondrotatable member defining a portion of the second aperture; and a thirdgear positioned in driving engagement with the first gear and the secondgear so that the first rotatable member and the second rotatable memberrotate relative to each other in geared coordination; wherein the firstedge being radially outward of the axis of the third gear and the secondedge being radially inward of the axis of the third gear, the first andsecond rotatable members being rotatably coupled to the pivot member torotate about common axis of rotation.
 2. The stroller of claim 1,wherein the pivot member being configured to be supportingly engaged byone of a front wheel support, a rear wheel support and a handle member,the first rotatable member being configured to be attached to adifferent one of the front wheel support, rear wheel support and handlemember, and the second rotatable member being configured to be attachedto yet another different one of the front wheel support, rear wheelsupport and handle member.
 3. The stroller of claim 1, wherein the firstaperture is elongated and the second aperture is elongated, and whereinthe elongated first and second apertures at least in part overlap. 4.The stroller of claim 3, wherein the first gear has a first pitchdiameter and the second gear has a second pitch diameter, with the firstpitch diameter and the second pitch diameter not being the same.
 5. Thestroller of claim 4, wherein the first pitch diameter of the first gearis sized to rotate one of a front wheel support, a rear wheel supportand a handle member to which the first rotatable member is configured tobe attached through a first angle of rotation from a folded position toan unfolded position, and wherein the second pitch diameter for thesecond gear is sized to rotate another one of the front wheel support,rear wheel support and handle member to which the second rotatablemember is configured to be attached through a second angle of rotationfrom a folded position to an unfolded position, with the first andsecond angles of rotation not being the same.
 6. The stroller of claim1, wherein the first gear has a first pitch and the second gear has asecond pitch different than the first pitch, and wherein the third gearincludes a first gear portion with the first pitch and a second gearportion with the second pitch, the first and second portions of thethird gear rotating as a unit, and the first gear portion of the thirdgear is positioned in the first aperture in driving engagement with thefirst gear and the second gear portion of the third gear is positionedin the second aperture in driving engagement with the second gear.
 7. Astroller, comprising: left and right side laterally spaced-apart firstmembers, each of the first members having a first end portion, a secondend portion, and connected through their first ends; left and right sidelaterally spaced-apart second members, each of the second members havinga first end portion, a second end portion, and connected through theirfirst ends; left and right side laterally spaced-apart third members,each of the third members having a first end portion, a second endportion, and connected through their first ends; and left and right sidelaterally spaced-apart folding assemblies, each of the left and rightside folding assemblies having a first rotatable plate and a secondrotatable plate rotatably mounted on a pivot member to pivot about acommon axis in parallel planes, the first rotatable plate having a firstaperture with a first gear and the second rotatable plate having asecond aperture with a second gear, each of the left and right sidefolding assemblies further having a third gear positioned in both thefirst and second apertures such that the first gear is formed at a firstedge portion of the first rotatable plate defining a portion of thefirst aperture and the second gear is formed at a second edge portion ofthe second rotatable plate defining a portion of the second aperture ofeach the left and right side folding assemblies, with the first edgebeing radially outward of the axis of the third gear and the second edgebeing radially inward of the axis of the third gear, such that the thirdgear is in driving engagement with the first gear and the second gear sothat the first rotatable plate and the second rotatable plate rotaterelative to each other in geared coordination.
 8. The stroller of claim7, wherein one of the second end portions of a first one of the first,second and third members being attached to the first rotatable plate,one of the second end portions of a different second one of the first,second and third members being attached to the second rotatable plate,and one of the second end portions of another different third one of thefirst, second and third members supporting the pivot member.
 9. Thestroller of claim 7, wherein the first and second rotatable plates eachhave a central portion with the central portions arranged inface-to-face juxtaposition.
 10. The stroller of claim 7, wherein thefirst and second rotatable plates each have a planar arm portionprojecting therefrom and in coplanar relation therewith, the one of thesecond end portions attached to the first rotatable plate being attachedto the arm portion thereof and the one of the second end portionsattached to the second rotatable plate being attached to the armthereof.
 11. The stroller of claim 7, wherein the first gear has a firstpitch diameter and the second gear has a second pitch diameter, with thefirst pitch diameter and the second pitch diameter not being the same.12. The stroller of claim 11, wherein the first pitch diameter of thefirst gear is sized to rotate the one of the first, second and thirdmembers attached to the first rotatable plate through a first angle ofrotation from a folded position to an unfolded position, and wherein thesecond pitch diameter for the second gear is sized to rotate the one ofthe first, second and third members attached to the second rotatableplate through a second angle of rotation from a folded position to anunfolded position, with the first and second angles of rotation notbeing the same.
 13. The stroller claim 7, wherein the first and secondrotatable plates are rotatably mounted to rotate about the common axisthrough spaced apart parallel rotation planes with the common axistransverse to the first and second rotatable plates, and the third gearis rotatably mounted to rotate about an axis transverse to the rotationplanes of the first and second rotatable plates and spaced apart fromthe common axis of the first and second rotatable plates.
 14. Thestroller of claim 13, wherein the first and second rotatable plates eachhave a planar arm portion projecting therefrom and in coplanar relationtherewith and rotatable with the first and second rotatable platesthrough the respective spaced apart parallel rotation planes of thefirst and second rotatable plates, the one of the second end portionsattached to the first rotatable plate being attached to the arm portionthereof and the one of the second end portions attached to the secondrotatable plate being attached to the arm thereof.
 15. The stroller ofclaim 7, wherein the third gear is rotatably mounted to rotate about anaxis parallel to and spaced apart from the common axis of the first andsecond rotatable plates.
 16. The stroller of claim 15, wherein the firstand second rotatable plates are rotatably mounted to rotate about thecommon axis with the first and second gears being in parallel rotationplanes.
 17. The stroller of claim 7, wherein the first gear has a firstpitch and second gear has a second pitch different than the first pitch,and wherein the third gear includes a first gear portion with the firstpitch and a second gear portion with the second pitch, the first andsecond portions of the third gear rotating as a unit, and the first gearportion of the third gear is positioned in the first aperture in drivingengagement with the first gear and the second gear portion of the thirdgear is positioned in the second aperture in driving engagement with thesecond gear.
 18. A stroller, comprising: a folding assembly comprising afirst rotatable member and a second rotatable member rotatably mountedto rotate relative to each other, the first rotatable member beingpositioned for rotation in a first rotation plane and the secondrotatable member being positioned for rotation in a second rotationplane spaced apart from the first rotation plane, the first rotatablemember having a first gear portion and the second rotatable memberhaving a second gear portion; and a third gear extending between thespaced apart first and second rotation planes and positioned such thatthe first rotatable member has a first aperture and the first gear isformed at a first edge portion of the first rotatable plate defining aportion of the first aperture and the second rotatable member has asecond aperture and the second gear is formed at a second edge portionof the second rotatable member defining a portion of the secondaperture, with the first edge being radially outward of the axis of thethird gear and the second edge being radially inward of the axis of thethird gear such that the third gear is in driving engagement with boththe first and second gear portions so that the first rotatable memberand the second rotatable member rotate relative to each other in gearedcoordination.
 19. The stroller of claim 18, wherein the first edgeportion is positioned at an elongated outward edge of the first apertureand the second edge portion is positioned at an elongated inward edge ofthe second aperture.
 20. The stroller of claim 19, wherein the firstgear portion has a first pitch diameter and the second gear portion hasa second pitch diameter, with the first pitch diameter and the secondpitch diameter not being the same.
 21. The stroller of claim 18, whereinthe stroller is movable between a folded position and an unfoldedposition, wherein the first pitch diameter of the first gear portion issized to rotate the first rotatable member through a first angle ofrotation from the folded position to the unfolded position, and whereinthe second pitch diameter for the second gear portion is sized to rotatethe second rotatable member through a second angle of rotation from thefolded position to the unfolded position, with the first and secondangles of rotation not being the same.
 22. The stroller of claim 18,wherein the first and second rotatable members are positioned forrotation in parallel first and second rotation planes, and the first andsecond rotatable members are rotatably mounted on a pivot member forsymmetric rotation about a common axis of rotation through the spacedapart parallel first and second rotation planes with the common axistransverse to the first and second rotatable members, and the third gearis rotatably mounted to rotate about an axis transverse to the first andsecond rotation planes of the first and second rotatable members andoutwardly spaced apart from the common axis of the first and secondrotatable members.
 23. The stroller of claim 18, wherein the first andsecond rotatable members are rotatably mounted on a pivot member forrotation about a common axis of rotation and the third gear is rotatablymounted to rotate about an axis parallel to and spaced apart from thecommon axis of the first and second rotatable members.
 24. The strollerof claim 18, wherein the first gear portion has a first pitch and secondgear portion has a second pitch different than the first pitch, andwherein the third gear includes a third gear portion with the firstpitch and a fourth gear portion with the second pitch, the third andfourth gear portions of the third gear rotating as a unit, and the thirdgear portion of the third gear is positioned in the first aperture indriving engagement with the first gear portion and the fourth gearportion of the third gear is positioned in the second aperture indriving engagement with the second gear portion.
 25. The stroller ofclaim 24, wherein the third gear portion of the third gear is a firstpinion gear and the fourth gear portion of the third gear is secondpinion gear, the first and second pinion gears being in coaxiallyarrangement.